1. Field of the Invention
The present invention relates to a decompression apparatus and an internal combustion engine having the decompression apparatus.
2. Discussion of the Background
Japanese Unexamined Patent Application Publication No. 2006-70831 discloses a decompression apparatus for an internal combustion engine. The contents of this publication are incorporated herein by reference in their entirety. This decompression apparatus includes a decompression shaft and a plunger. In the decompression shaft, a valve cam for driving an engine valve is provided on a cam shaft. The plunger is accommodated in a plunger hole which is formed in the cam shaft so as to be movable in a radial direction of the cam shaft. The plunger, operated by the decompression shaft, moves between a decompression position and a decompression cancel position in the plunger hole. At the decompression position, the plunger presses the engine valve and opens it. At the decompression cancel position, the engine valve is not opened.